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MattermostApplication

CVE-2023-47168

MEDIUM · 6.1 CVSS v3.1 Published 2023-11-27
Fix available
A fix is available. Upgrade to after 9.0.1 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Mattermost fails to properly check a redirect URL parameter allowing for an open redirect was possible when the user clicked "Back to Mattermost" after providing a invalid custom url scheme in /oauth/{service}/mobile_login?redirect_to=

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Mattermost fails to properly validate the redirect_to parameter in the OAuth mobile login endpoint (/oauth/{service}/mobile_login?redirect_to=). This allows an attacker to craft malicious URLs that appear to originate from Mattermost but redirect users to attacker-controlled external sites, constituting an open redirect vulnerability.

MitigationImplement strict validation of the redirect_to parameter to ensure it only allows relative URLs or trusted internal domains; reject any redirect URLs pointing to external/untrusted hosts before processing the OAuth flow.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MattermostApplication
Affected:<= 7.8.12>= 8.0.0, <= 8.1.3>= 9.0.0, <= 9.0.1= 9.1.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Mattermost server version
    Run 'mattermost version' from the command line or access the system console and navigate to About > Mattermost to view the version number.
    Affected if The installed version falls within any of these ranges: <= 7.8.12, 8.0.0 to 8.1.3, 9.0.0 to 9.1.0, or equals 9.1.0
  2. Verify OAuth mobile login is accessible
    Confirm that the Mattermost server has OAuth providers configured and mobile login is not disabled. Check the system console under Authentication > OAuth 2.0 to see if any OAuth provider (such as GitLab, Google, or Office 365) is enabled.
    Affected if OAuth providers are enabled and mobile login endpoint /oauth/{service}/mobile_login is accessible to users
  3. Confirm redirect_to parameter handling
    Review the server configuration or proxy logs for how the redirect_to query parameter is processed in the OAuth mobile login flow. Check if any validation exists to restrict redirect URLs to relative paths or internal domains only.
    Affected if No validation is implemented to reject external domains in the redirect_to parameter, allowing arbitrary URL redirection

You are affected if your Mattermost version is 7.8.12 or earlier, 8.0.0 through 8.1.3, 9.0.0 through 9.0.1, or exactly 9.1.0, and OAuth mobile login is enabled on your server.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 9.0.1
Interim mitigation

Implement strict validation of the redirect_to parameter to ensure it only allows relative URLs or trusted internal domains; reject any redirect URLs pointing to external/untrusted hosts before processing the OAuth flow.

Recommended fix Moderate confidence

Upgrade to 7.8.13, 8.1.4, 9.0.2, 9.1.1, or latest 9.x release (recommended: 9.5.x)

  1. 1. Identify the current Mattermost version by checking the system console or running 'mattermost version'
  2. 2. If running <= 7.8.12: Upgrade to version 7.8.13 or later
  3. 3. If running >= 8.0.0 and <= 8.1.3: Upgrade to version 8.1.4 or later
  4. 4. If running >= 9.0.0 and <= 9.0.1: Upgrade to version 9.0.2 or later
  5. 5. If running 9.1.0: Upgrade to version 9.1.1 or later
  6. 6. For the latest stable release with all security fixes, upgrade to the most recent 9.x release (e.g., 9.5.x)
  7. 7. After upgrade, verify the fix by testing the oauth redirect flow at /oauth/{service}/mobile_login?redirect_to= with an external URL
Caveat Review Mattermost release notes for version-specific changes; major version upgrades (e.g., 7.x to 8.x, 8.x to 9.x) may include database migrations and configuration changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mattermost Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-47168 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data